| We have used spincoating to deposit wedge-shaped polymer films in which the film thickness varies in the radial direction. The local roughness of the polymer wedge films is comparable to that of spincoated polymer films of uniform thickness, as measured using atomic force microscopy. Using local probes such as focused ellipsometry and atomic force microscopy, we have characterized the shape of these films, as well as a unique, reproducible feature which occurs at the inner edge of the wedge film. We have derived an analytical expression of the radial dependence of the film thickness which contains two parameters. We have used the analytical expression to perform a nonlinear least squares fit of the measured radial thickness profiles for ten different polymer wedge films prepared under different deposition conditions. We have used single wedge polymer films and wedge polymer films incorporated into multilayer systems to study the detailed film thickness dependence of different physical phenomena: thin film dewetting, pattern formation in supported bilayer and trilayer systems, and the glass transition temperature in supported PS wedge films. |
